VANCOUVER -- B.C. Premier Christy Clark’s chief of staff, Ken Boessenkool, resigned abruptly Monday over an “incident of concern.”

Clark said an incident involving Boessenkool occurred a few weeks ago but privacy laws prevented her from disclosing why he stepped down.

“This was a completely unexpected event. This is not the sort of thing that anyone can anticipate,” Clark said at a news conference Monday. “I learned about it a couple of weeks ago and that is when the investigation began.”

But according to sources, the incident occurred Sept. 7, after many Liberal government politicians and staff members had participated at a golf tournament at the Metchosin Golf and Country Club just west of Victoria, to raise money for the B.C. Liberal party.

By tradition, media were also present, but the event is considered off-the-record, to allow politicians and reporters to socialize freely.

However, one source said Boessenkool and others later moved the party to a pub a few blocks away from the Legislature.

Details of the incident are uncertain, but shortly thereafter the Premier’s office began an investigation of Boessenkool’s conduct at the pub.

When the investigation was complete, the Premier met with Boessenkool. She said they both agreed he needed to resign, which he did.

Clark refused to comment on whether the incident involved a political staffer or whether Boessenkool was accused of groping a woman. She indicated the incident was not criminal in nature.

Boessenkool, a former staffer for Prime Minister Stephen Harper, expressed his regret in his letter of resignation.

“…I acted inappropriately,” he wrote. “I was wrong, regretted my behaviour very much and immediately and unconditionally apologized.”

“Notwithstanding my genuine apology and sense of regret, and following my meeting with you earlier today I tender my letter of resignation as your chief of staff effective immediately.”Boessenkool said he would return to Calgary to be with his family from whom he’d been separated on a weekly basis most of the past eight months and who he had “also let down.”

“Nothing should stand in the way of your successful leadership,” he added in his letter to Clark.

Clark replaced Boessenkool with Dan Doyle, who left BC Hydro’s board for his new position. Doyle is a former VANOC (Vancouver Olympic Committee) executive vice-president responsible for venue construction.

“Dan is a man who has committed himself to public service for 36 years. He is the guy who can step in and make sure we don’t miss a beat,” Clark added.

--with files from Erica Bulman and Richard Zussman